<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>弹丸3.5</title>
  <style>
    #bigblock {
      width: 647px;
      height: 187px;
    }
    #bigblock div{
      margin-top: 10px
    }
    .faketopline {
      width: 647px;
      height: 1px;
      background-color: #7eb8ec;
    }
    .littleblocks div{
      width: 90px;
      height: 28px;
      background-color: #0873c0;
    }
    .sillybunks {
      width: 647px;
      height: 128px;
      padding-top: 39px
    }
    .sillybunks div{
      float: left;
      width: 209px;
      height: 118px;
      background-color: #cccccc;
    }
  </style>
</head>
<body>
  <div id="bigblock">
    <div class="faketopline"></div>
    <!--这里有一个双倍空格-->
    <div class="littleblocks">
       <div style="float: left"></div>
       <div style="float: right"></div>
     </div>   
      <div class="sillybunks">
      <div></div>
      <div style="margin-left: 10px;margin-right: 10px"></div>
      <div></div>
    </div>
  </div>
</body>
</html>